<!DOCTYPE html>
<html lang="en">
<head>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.12"></script>
</head>
<body>
    <div id="app">
        <my-com></my-com>
    </div>
    <script>
        var comElement=Vue.extend({
            template:'<h3>组件名称使用的规则</h3>'
        })
        Vue.component('myCom',comElement)
        var app=new Vue({
            el:'#app'
        });
    </script>
</body>
</html>